Sorry. Don't think that makes any sense. Lets try again.

I have a large amount of data.
Everymonth the data starts again with Column A incrementing by one from
200908 in August to 200909 in september.
We want to know the difference between the number in Column T from august
and column T from September.
So how do we search through the spread sheet for first the customer number
in Column D and then the previous period which is A -1

Hope that helps.

"Mark B" wrote:

Hello Lovely Excel People (flattery works sometimes)
OK so I have a spreadsheet (I know amazing)
With lots of data.
Column A is period so 200908 is August 2009
Column D is a Customer Number.
Column Y I want to be Column T minus Colum T of Customer in "D" in Row A -1
So for instance we are using line 3500
in column Y it would be D3500= 12345
Find 12345 in the spread sheet where Column A = A3500-1

OK anyone have any ideas or any questions to make this actually make sense?